Multiple IS10 rearrangements in Escherichia coli.
Multiple IS10 rearrangements in Escherichia coli.
复制标题
大肠杆菌中的多重 IS10 重排。
DOI：
10.1016/0022-2836(84)90390-5
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发表时间：
1984
影响因子：
5.6
通讯作者：
Kleckner,N
中科院分区：
文献类型：
--
作者：
Raleigh,EA;Kleckner,N
我们研究了在含有转座子Tn10的大肠杆菌K12菌株中发生了多个转座子促进的染色体重排。我们发现，单个Tn10元件及其两个紧密间隔的插入序列(IS10)元件经常引起复杂的重排，可被解释为两个“经典”IS10事件的总和。使用在较远分离位置包含差异标记的Tn10元件的菌株，我们研究了IS70促进的重排发生在细胞范围内的可能性，正如预期的那样，如果细胞偶尔会经历所有IS10转位事件都被激活的短暂时期，并穿插着较长的相对静止期。在我们的实验条件下，我们没有发现强烈的(>；60倍)周期性的细胞范围内激活的证据。本实验的敏感性是使用具有异质、波动突变率的人群中双突变积累的表达式来评估的(见附录)。我们讨论了几种机制，两个紧密相连的IS10元件可以经历耦合的双重事件而不是整个细胞范围的激活：小染色体区域的局部激活、顺式作用转座酶蛋白的周期性突发合成，和/或实际参与一个重排事件的元件立即启动第二个连续事件的倾向。我们赞成最后一种可能性。
We have investigated the occurrence of multiple transposon-promoted chromosomal rearrangements inEscherichia coliK12 strains containing transposon Tn10. We show that a single Tn10 element, with its two closely spaced insertion sequence (IS10) elements, frequently gives rise to complex rearrangements that can be accounted for as the sum of two “classical” IS10 events.Using a strain containing differentially marked Tn10 elements at widely separated locations, we have investigated the possibility that IS70-promoted rearrangements occur in cell-wide “bursts”, as expected if cells could occasionally undergo brief periods when all IS10 transposition events were activated, interspersed with longer periods of relative quiescence. We find no evidence for strong (> 60-fold), periodic cell-wide activation under our experimental conditions. The sensitivity of this experiment has been evaluated using an expression for the accumulation of double mutations in populations with heterogeneous, fluctuating mutation rates (see Appendix).We discuss several mechanisms by which two closely linked IS10 elements could undergo coupled double events without cell-wide activation: local activation of small chromosomal regions, periodic bursts of synthesis ofcis-acting transposase protein, and/or a propensity for elements that have actually engaged in one rearrangement event to initiate a second successive event immediately thereafter. We favor the last possibility.